The present invention relates to an ATM (Asynchronous Transmission Mode) communication system and, more particularly, to an ATM communication system designed to be used in a private area.
In recent years, ATM techniques have been vigorously studied and developed to realize a B-ISDN. As for public networks, public network ATM switching units and ATM cross-connections have been vigorously developed. The carriers in various countries have gradually been constructing ATM networks by using such ATM switching units and ATM cross-connections. The ATM communication techniques have been applied to the business field as well; many benders are selling simple ATM switching units called ATM switches and constructing private networks.
ATM is a transmission scheme characterized in that digital information is transmitted by using a cell which is a short packet having a fixed length. By using short fixed-length packets, each terminal transmits cells as needed. Since each terminal can use the transmission capacity of a physical link relatively freely, ATM is suited to multi-rate communication. In addition, ATM can be used for speech communication or the like in which a delay time exerts a great influence on the communication quality. Furthermore, ATM allows high-speed processing because fixed-length cells are exchanged. Owing to these characteristics, ATM switching units for public and private networks have come into widespread use.
If public and private networks to which ATM communication is applied are widely used, for example, high-speed LAN connection between offices can be realized. A multimedia terminal may be installed in a store in a remote place. In this case, designs for clothes are presented to customers who visit the store, and the clothes ordered by the customers are tailored, thus proving convenient services. As users enjoy the benefits of ATM communication in business and privately, the users want to install multimedia terminals and LANs (Local Area networks) in their homes.
As described above, with the use of ATM, real-time multi-rate communication can be provided, and various types of existing/novel information sources/information services can be properly handled. If, therefore, ATM communication techniques are used, communication between the apparatuses and the information sources in homes can be realized. However, conventional ATM communication apparatuses have been applied to public networks or private networks in the business field and designed to have throughputs/functions/reliability high enough to properly cope with these fields. For this reason, these apparatuses are expensive. In addition, since the conventional ATM communication apparatuses are designed on the assumption that they are maintained and operated by experts, they require complicated operations. For this reason, the conventional ATM communication apparatuses are not suitable for home use without any modification.
As a communication apparatus construction technique for realizing multimedia communication in homes, a standard called P1394 has been proposed by IEEE (The Institute of Electrical and Electronics Engineers). This standard has been established mainly for a communication path between a personal computer and an external storage unit. Recently, however, a packet/line switching function is added to this standard to handle continuous system information. With the addition of this function, for example, the number of messages assigned to one frame must be dynamically changed to transmit MPEG2 messages. The implementation of this function, therefore, becomes increasingly complicated as the transmission rates of information from information sources vary. That is, P1394 cannot cope with various types of existing/novel information sources/information services at a low cost.
As described above, since the conventional ATM communication apparatuses are expensive and require complicated operations, they are not suitable for home use. In addition, the conventional communication apparatuses desired for home use cannot cope with various types of existing/novel information sources/information services in the future.